dt-bindings: serial: Convert STM32 UART to json-schema

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/serial/st,stm32-uart.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

maintainers:

  - Erwan Le Ray <erwan.leray@st.com>

title: STMicroelectronics STM32 USART bindings

allOf:

  - $ref: rs485.yaml

properties:

  compatible:

    enum:

      - st,stm32-uart

      - st,stm32f7-uart

      - st,stm32h7-uart

  reg:

    maxItems: 1

  interrupts:

    maxItems: 1

  clocks:

    maxItems: 1

  resets:

    maxItems: 1

  label:

    description: label associated with this uart

  st,hw-flow-ctrl:

    description: enable hardware flow control

    $ref: /schemas/types.yaml#/definitions/flag

  dmas:

    minItems: 1

    maxItems: 2

  dma-names:

    items:

      enum: [ rx, tx ]

    minItems: 1

    maxItems: 2

  wakeup-source: true

  rs485-rts-delay: true

  rs485-rts-active-low: true

  linux,rs485-enabled-at-boot-time: true

  rs485-rx-during-tx: true

required:

  - compatible

  - reg

  - interrupts

  - clocks

additionalProperties: false

examples:

  - |

    #include <dt-bindings/clock/stm32mp1-clks.h>

    usart1: serial@40011000 {

      compatible = "st,stm32-uart";

      reg = <0x40011000 0x400>;

      interrupts = <37>;

      clocks = <&rcc 0 164>;

      dmas = <&dma2 2 4 0x414 0x0>,

             <&dma2 7 4 0x414 0x0>;

      dma-names = "rx", "tx";

      rs485-rts-active-low;

    };

...

* STMicroelectronics STM32 USART

Required properties:

- compatible: can be either:

  - "st,stm32-uart",

  - "st,stm32f7-uart",

  - "st,stm32h7-uart".

  depending is compatible with stm32(f4), stm32f7 or stm32h7.

- reg: The address and length of the peripheral registers space

- interrupts:

  - The interrupt line for the USART instance,

  - An optional wake-up interrupt.

- clocks: The input clock of the USART instance

Optional properties:

- resets: Must contain the phandle to the reset controller.

- pinctrl: The reference on the pins configuration

- st,hw-flow-ctrl: bool flag to enable hardware flow control.

- rs485-rts-delay, rs485-rx-during-tx, rs485-rts-active-low,

  linux,rs485-enabled-at-boot-time: see rs485.txt.

- dmas: phandle(s) to DMA controller node(s). Refer to stm32-dma.txt

- dma-names: "rx" and/or "tx"

- wakeup-source: bool flag to indicate this device has wakeup capabilities

- interrupt-names, if optional wake-up interrupt is used, should be:

  - "event": the name for the interrupt line of the USART instance

  - "wakeup" the name for the optional wake-up interrupt

Examples:

usart4: serial@40004c00 {

	compatible = "st,stm32-uart";

	reg = <0x40004c00 0x400>;

	interrupts = <52>;

	clocks = <&clk_pclk1>;

	pinctrl-names = "default";

	pinctrl-0 = <&pinctrl_usart4>;

};

usart2: serial@40004400 {

	compatible = "st,stm32-uart";

	reg = <0x40004400 0x400>;

	interrupts = <38>;

	clocks = <&clk_pclk1>;

	st,hw-flow-ctrl;

	pinctrl-names = "default";

	pinctrl-0 = <&pinctrl_usart2 &pinctrl_usart2_rtscts>;

};

usart1: serial@40011000 {

	compatible = "st,stm32-uart";

	reg = <0x40011000 0x400>;

	interrupts = <37>;

	clocks = <&rcc 0 164>;

	dmas = <&dma2 2 4 0x414 0x0>,

	       <&dma2 7 4 0x414 0x0>;

	dma-names = "rx", "tx";

};